JP4069748B2 - Vehicle front structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pair of extension side members extending in the vehicle front-rear direction, a dash cross member having both ends connected to the pair of extension side members, and a rear portion of a subframe fixed to a lower end surface via a fastening member. The vehicle front part structure provided with these.
[0002]
[Prior art]
In recent years, many vehicles have been developed that secure a large cabin space by flattening the floor surface of the passenger compartment. In such vehicles, a frame such as an extension side member or a dash cross member is provided under the floor panel. Many vehicle structures are used (see Patent Document 1). To the dash cross member, a subframe for fixing a suspension, an engine, a mission, and the like to the underbody is attached using bolts.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 2002-240739 (FIGS. 1 to 5)
[0004]
[Problems to be solved by the invention]
However, since the subframe is attached so as to support the dash cross member and the like from the lower surface side, when an impact (energy) is applied from the front of the vehicle, the sub frame, the dash cross member, and the fastening portion attached by the bolt There was a problem that the rigidity in the vehicle front-rear direction at the (bolt fastening location) tends to be insufficient.
[0005]
Furthermore, since the dash cross member is fastened to the extension side member at both ends, there is a problem that it is difficult to efficiently disperse and absorb the energy transmitted through the fastening portion.
[0006]
The present invention has been made in view of the above problems, and a vehicle capable of efficiently dispersing and absorbing energy input from the front of the vehicle at the fastening portion between the subframe and the dash cross member and the dash cross member. It is an object to provide a front structure.
[0007]
[Means for Solving the Problems]
In order to solve the above-described problem, an invention according to claim 1 includes a pair of front side members extending in the vehicle front-rear direction, a subframe disposed below the front side member, and a vehicle front-rear direction. A pair of extension side members extending and having front portions connected to the rear portions of the front side members , both ends are connected to the front portions of the pair of extension side members, and the rear portion of the subframe is a fastening member on the lower surface a dash cross member that is fixed through, characterized in that the reinforcement member fixed to the rear side surface of the inner surface and the dash cross member of the extension side member is provided on the vehicle rear side of the dash cross member And
[0008]
By providing the reinforcing member on the vehicle rear side of the dash cross member, the energy from the front of the vehicle applied to the dash cross member and the fastening member can be distributed to the extension side member, and the energy can be absorbed efficiently. . For this reason, it is possible to prevent deformation of the dash cross member, retreat of the fastening member, and the like, and it is possible to improve the rigidity in the vehicle front-rear direction at the fastening portion (fastening portion of the fastening member) between the dash cross member and the subframe. It becomes.
[0009]
The invention according to claim 2 is the vehicle front structure according to claim 1, wherein the reinforcing member is provided so that the lower surface of the reinforcing member and the lower surface of the dash cross member are flush with each other. To do.
[0010]
By installing the reinforcing member so that the lower surface of the reinforcing member and the lower surface of the dash cross member are flush with each other, energy applied to the fastening portion (fastening portion of the fastening member) between the dash cross member and the subframe is more efficient. Therefore, the rigidity of the fastening portion can be further improved.
[0011]
According to a third aspect of the present invention, in the vehicle front portion structure according to the first or second aspect, the extension side member is positioned at an extension side member front located at the front of the vehicle and behind the extension side member front. An extension side member center is connected to each other, and the reinforcing member is fixed to both side surfaces of an inner side surface of the extension side member front and a vehicle inner side ment of the extension side member center.
[0012]
The reinforcing member is fixed to both side surfaces of the inner side surface of the extension side member front and the vehicle inner side ment of the extension side member center, so that the energy input to the subframe from the front of the vehicle is transmitted to the extension side member front. Since it can be distributed to both the extension side member center, the energy distribution can be distributed over a wide range of extension side members.
[0013]
Further, by dispersing the energy over a wide range of the extension side members, it is possible to prevent the energy from concentrating on the connecting portion between the extension side member front and the extension side member center, the strength of which tends to decrease.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a vehicle front structure according to the present invention will be described with reference to the drawings.
[0015]
The vehicle front portion structure 1 according to the present invention includes a front side member 2, an extension side member 3, a floor panel 4, a dash cross member 5, and a reinforcing member 6, as shown in FIGS.
[0016]
As shown in FIG. 3, the floor panel 4 includes a floor surface portion 4a that forms a flat floor surface, a dash panel portion 4b that partitions the vehicle compartment R and the engine room r, a floor surface portion 4a, and a dash panel portion 4b. The toe board portion 4c is integrally formed with the toe board portion 4c, and the toe board portion 4c is inclined at approximately 45 degrees with respect to the horizontal floor surface portion 4a, and the dash panel surface 4b is erected substantially vertically. Yes.
[0017]
The front side members 2 and 2 are provided as a pair so as to be located on the vehicle front side of the toe board portion 4c and on both the left and right sides of the vehicle. At the front end portion of the front side member 22, mounting seat portions 2 a and 2 a that support the front portion of the subframe 7 are formed.
[0018]
The extension side members 3, 3 are positioned below the front side members 2, 2 and extend in the vehicle front-rear direction so as to be along the bottom side of the toe board portion 4 c and the floor surface portion 4 a of the floor panel 4. The extension side members 3, 3 are provided in a pair so as to be positioned at both left and right ends of the vehicle, and the front upper surfaces of the extension side members 3, 3 are connected to the rear lower surfaces of the front side members 2, 2.
[0019]
Side sills 8, 8 are provided in parallel to the extension side members 3, 3 on the vehicle outer side of the extension side member 3, and the side sills 8, 8 and the extension side members 3, 3 are connected via the outriggers 9, 9. Are connected.
[0020]
The extension side member 3 includes an extension side member front 3a located on the front side of the vehicle and an extension side member center 3b extending rearward thereof, and a rear end portion of the extension side member front 3a and an extension side member The front end portion of the center 3b is connected to each other to form a connecting portion 3c.
[0021]
A dash cross member 5 whose both ends are connected to a pair of extension side member fronts 3a and 3a is provided at the vehicle front end portion of the lower surface of the floor surface portion 4a. Two fastening holes are formed in the lower surface of the dash cross member 5, and bolts 10 for fixing the rear portion of the subframe 7 to the dash cross member 5 are inserted into the fastening holes. As shown in FIGS. 2 and 3, the subframe 7 is fixed to the dash cross member 5 and the mounting seat portions 2 a and 2 a via bolts 10 and 10.
[0022]
A pair of reinforcing members 6 and 6 are provided behind the dash cross member 5. The reinforcing members 6 and 6 have a triangular prism shape standing downward on the lower surface of the bottom surface portion 4a, the vehicle front side is abutted and fixed to the rear side of the dash cross member 5, and the vehicle outer side is the extension side member. The front side 3a and the extension side member center 3b are fixed in contact with the inner side surfaces. Further, the lower surfaces of the reinforcing members 6, 6 are flush with the lower surface of the dash cross member 5.
[0023]
In the vehicle front structure 1 configured as described above, when energy is applied from the front of the vehicle due to a vehicle collision or the like, the energy is connected to the fastening portion 11 (bolt between the subframe 7 and the dash cross member 5 via the subframe 7. 10), the bolt 10 and the dash cross member 5 are pushed down to the rear of the vehicle. At this time, since the reinforcing member 6 is provided behind the dash cross member 5, the reinforcing member 6 absorbs energy applied to the dash cross member 5, and the absorbed energy is absorbed by the extension side member front 3a and the extension side. Distribute to member center 3b. For this reason, by installing the reinforcing member 6, the input energy can be efficiently dispersed and absorbed in the frame constituting the vehicle front structure.
[0024]
Moreover, since energy can be prevented from concentrating only on the dash cross member 5 and the bolt 10 due to energy dispersion, deformation of the dash cross member 5 and retraction of the fastening position of the bolt 10 can be prevented. Further, the rigidity in the vehicle front-rear direction at the fastening portion 11 (fastening location of the bolt 10) between the dash cross member 5 and the subframe 7 can be improved.
[0025]
Further, since the reinforcing member 6 is installed so that the lower surface of the reinforcing member 6 and the lower surface of the dash cross member 5 are flush with each other, the fastening portion 11 (fastening the bolt 10) between the dash cross member 5 and the subframe 7 The energy applied to the portion) can be transmitted to the reinforcing member 6 more efficiently, and the rigidity of the fastening portion 11 can be further improved.
[0026]
Further, since the reinforcing member 6 is fixed to both side surfaces of the inner side surface of the extension side member front 3a and the inner side surface of the extension side member center 3b, the energy input to the subframe 5 from the front of the vehicle is transferred to the extension side member. It is possible to disperse both the member front 3a and the extension side member center 3b, and it is possible to disperse energy in a wide range of the extension side member 3.
[0027]
Further, by dispersing the energy over a wide range of the extension side member 3, it is possible to prevent the energy from concentrating on the connecting portion 3c between the extension side member front 3a and the extension side member center 3b having low strength. Become.
[0028]
As mentioned above, although the vehicle front part structure which concerns on this invention was demonstrated using drawing, the vehicle front part structure which concerns on this invention is not limited to the thing of the structure mentioned above.
[0029]
【The invention's effect】
As described above, according to the first aspect of the present invention, the reinforcement member is provided on the vehicle rear side of the dash cross member, so that the energy from the vehicle front applied to the dash cross member and the fastening member is extended to the extension side. It can be distributed to the members, and energy can be absorbed efficiently. For this reason, it is possible to prevent deformation of the dash cross member, retreat of the fastening member, and the like, and it is possible to improve the rigidity in the vehicle front-rear direction at the fastening portion (fastening portion of the fastening member) between the dash cross member and the subframe. It becomes.
[0030]
According to the second aspect of the present invention, by installing the reinforcing member so that the lower surface of the reinforcing member and the lower surface of the dash cross member are flush with each other, the fastening portion (the fastening member of the fastening member) Since the energy applied to the fastening part) can be more efficiently dispersed using the reinforcing member, the rigidity of the fastening part can be further improved.
[0031]
According to the invention of claim 3, the reinforcing member is fixed to both side surfaces of the inner side surface of the front of the extension side member and the vehicle inner side ment of the extension side member center, so that the input to the subframe from the front of the vehicle. Since the generated energy can be distributed to both the extension side member front and the extension side member center, the energy distribution can be distributed over a wide range of the extension side member.
[0032]
Further, by dispersing the energy over a wide range of the extension side members, it is possible to prevent the energy from concentrating on the connecting portion between the extension side member front and the extension side member center, the strength of which tends to decrease.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a vehicle front structure according to the present invention from below a vehicle.
FIG. 2 is a bottom view showing a vehicle front structure according to the present invention.
3 is a cross-sectional view showing an AA cross section of the vehicle front portion structure shown in FIG. 2. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Vehicle front part structure 2 Front side member 2a Mounting seat part 3 Extension side member 3a Extension side member front 3b Extension side member center 3c Connection part 4 Floor panel 5 Dash cross member 6 Reinforcement member

Claims (3)

A pair of front side members (2) extending in the longitudinal direction of the vehicle;
A subframe (7) disposed below the front side member;
A pair of extension side members (3) extending in the vehicle front-rear direction and having a front portion connected to a rear portion of the front side member (2) ;
A dash cross member (5) having both ends connected to the front part of the pair of extension side members (3) and the rear part of the subframe (7) fixed to the lower surface via a fastening member (10). ,
The reinforcing member (6) fixed to the inner side surface of the extension side member (3) and the rear side surface of the dash cross member (5) is provided on the vehicle rear side of the dash cross member (5). Vehicle front structure.   The vehicle front structure according to claim 1, wherein the reinforcing member (6) is provided so that a lower surface of the reinforcing member (6) and a lower surface of the dash cross member (5) are flush with each other. . The extension side member (3) is formed by connecting an extension side member front (3a) located at the front of the vehicle and an extension side member center (3b) located behind the extension side member front (3a).
The reinforcing member (6) is fixed to both side surfaces of an inner side surface of the extension side member front (3a) and an inner side surface of the extension side member center (3b). The vehicle front structure according to 2.

Images